DIY Vacuum-Estim-Cylinder

Today i experimentes with my two chamber sucktion cylinder. I used two different pumps for the glans chamber und the penis shaft chamber. (normaly i use just one pump for both chambers) For the pensishaft chamber, i used a stronger pump and a magnetic valve, that seals if the pump is working and leavs air back in, when the pump is of.
This changes in cycle of 3 seconds. This results in an interesting  effect. It sucks the penis shaft into the lower chamber realy strong. If the magnetic valve opens and air flows back into the chamber, the glans gets sucked intwo the upper chamber again. This i a realy realy wierd feeling. It feels like you penis gets pumped up and streches again and again, in cycels of 3 seconds. A lot of fun! Especialy in combination with the estim-device.

   

I made some nice gifs for your amusemenst:

           

....Brrrrrrrrt.......suck-suuck-suuuck-Suuuuck-SUUUUUCK!!!!!!!!......tickle-tihickle-tihihickle-tihihihickle-TIHIHIHIHICKLE!!!!!!!!.........squeeze-squeeeze-squeeeeze-SQUEEEEEZE!!!!!!!!!......... Brrrrrrrrt.......suck-suuck-suuuck-Suuuuck-SUUUUUCK!!!!!!!!......tickle-tihickle-tihihickle-tihihihickle-TIHIHIHIHICKLE!!!!!!!!.........squeeze-squeeeze-squeeeeze-SQUEEEEEZE!!!!!!!!!......... Brrrrrrrrt.......suck-suuck-suuuck-Suuuuck-SUUUUUCK!!!!!!!!......tickle-tihickle-tihihickle-tihihihickle-TIHIHIHIHICKLE!!!!!!!!.........squeeze-squeeeze-squeeeeze-SQUEEEEEZE!!!!!!!!!......... Brrrrrrrrt.......suck-suuck-suuuck-Suuuuck-SUUUUUCK!!!!!!!!......tickle-tihickle-tihihickle-tihihihickle-TIHIHIHIHICKLE!!!!!!!!.........squeeze-squeeeze-squeeeeze-SQUEEEEEZE!!!!!!!!!.........
You can´t say if you want it to stop or to go on!